The opposing foreign policy teams of Hillary Clinton and Barack Obama had their genesis 46 years ago in the 1962 class of diplomatic trainees at the U.S. State Department. Anthony Lake, a Wasp from Connecticut, and Richard Holbrooke, the son of European-Jewish immigrants, arrived in Washington that summer, destined to become two of the best diplomats of their generation. They became close friends and were posted together to Vietnam one year later. Lake would later sign Holbrooke's wedding certificate, and Holbrooke eventually became the godfather of one of Lake's daughters. They also became competitors, rising together in a tight orbit and...